Color couplers for photographic color development



July 31, 1945 OFFICE 001103 COUPLEBS FOR PHOTOGRAPHIC Y COLORDEVELOPMENT Honore Verkinderen, Morisel, and Norbert Vankeirsbilok,Lenven, Belgium: vested in the Alien Custodian Property No Drawing.

This invention relates to photographic color development and toprocesses of color development for use in connection with colorphotography.

It is known that color photographic images may be formed by using adeveloper which iorms a colored and insoluble oxidation product duringdevelopment, the colored product thus formed scribed a process of colordevelopment by means oi compounds oi the general formula:

. Y-rCHri-B where Y is one of the electro-negative groups CR- or 2.00-(wherexis anelhior aryl group, substituted or unsubstitimd) while B isan arylor hctcrocyclo-substitutcd amino roup.

the invention are compounds having the general formula: "Ii "if --on|-xwherein In an electro-negative such as acyl-, cyano-etc.. and

YisanorganicradicalfsuchashydrogemalkyloraryLthelasttwomaybcsubstitutedor unsubstituted.

0 schen Gesellschait" 22, (1889) page 2414. The

40 forming color photographic images by the incor- Applicatlon April 18,.1841, Serial In Great Britain December 11,

A 2 Claims. ((31. 95-88) Examples of such couplers are:

8 bensyi-il aoetonyl-1,8,4-oxodissolo 'Ihese color couplers, on couplingwith the oxidation product oi an aromatic-amino-developerduring thedevelopment of the latent image, form a yellow wlor when belonging tothe class as illustrated by Example 1, and an orange color whenbelonging to the class as illustrated by Example 2.

These compounds are prepared by the method described in Berichte derDeutschen Chemi- .compou nd of Example 2 is prepared by reactin cuprouscyanide with 3-phenyl-5 chloroacetyl- 1,2,4 oxodiaaole which can beobtained by the process described in Berichte" 18 (1886) page Thepresent invention consists, broadly, in the process of producingcolor-photographic images by the use of color couplers as above defined.

Thus the invention comprises the process of poration, in thephotographic emulsion, before or after coating, of a color coupler asabove deiineii and, further. the process of developing a latentphotographic image by means of a color developer comprising in additionto an aromatic amino developing agent a color. coupler as above defined.

Thus the invention includes the method of color development whichcomprises developing a latent photographic image by means 01' anaromatic amino developer in the presence of color couplers as abovedefined, and eliminating the silver image which is formed duringdevelopment so that a clear and transparent color image remains.

The invention also consists in new or improved color iorming developerscomprising, in addition to an aromatic amino developing agent, colorcouplers as above, defined.

The present invention .iurther includesphoto- 2 l s,sso,soc

graphic elements having at least one layer con- B essentially of theproduct resulting from the taining maker and transparent image composedcm-C c-N coupling in situ during development of color couplers as abovedefined, with the oxidation 5 K Cnhco product of an aromatic aminodeveloping agent.

The aromatic amino compounds which may be uethmol' "com" 100 used asdeveloping asents in the present inventlon include the mono-, diandtri-amino-aryl- For m B to compounds. Among the mono-amino developingRosanna 4 agents may be mentioned amino-phenols and amlno-cresols andtheir halogen derivatives and 4 amino-naphthols. I i

The developing agents preferably used and g pan phenylened e g 3 havinghitherto given the best results in connecl5 s u tion with the presentinvention are the aromatic fi fi g zgfl'i "g" :3 orthoand para-diamines.such as para-phenyl- 7 sodium hydroxide 2 enedlamine and itssubstitution products. These water h" 1000 developing agents may besubstituted in one aminogroup'orintheringorinbothJormingzo 3 compoundssuch as: NR diethyl-para-phenylenedlamine. N I

Mi mmum QE, .C Q .CH' "I" 3 para-phenylenediamine, and n. v S-amlno-Bdlmethylamino-tolume.

These compounds are usually kept in the salt 100 form such ashydrochloride or sillllhlte. For B 'dded The following developersolutions may be used mu 5 togiveacolorimageaecordingtcthepreaentaoinvention: A

N-N' diethyl-para-phenylenediamine 4 n01 5 2 1mdiethyl-para-phenylenediamine odiu m v ust --s-- m g g Sodium carbonate(cryst) g 80 Sodium sulphite (cryst.) g-.. as Sodium hvdmflde --s-- 2Sodium carbonate (cmt) e so Weter Sodlumhydroxide g 2 3 Water mm 1000 40B C---N CaHr-C-N 1k )i-om-co-cm a -cm-oo-om g s 0 Methanol Mm 100Methanol m 100 l'bruse B is ldded toA. For use 8 is added to A. Foams 8Ibnmu 2 w A A N-N' diethyl-para-phenylenediamine v S-amino-Q'dimcthylamino-toluene hydro- H01 I 2 chloride ..g- 4 vSodium sulphite(crystJ g 25 Sodium sulphite (crvst.)---. g- 10 Sodium carbonate (cry t)3-- 60 Potassiumcarbouate g 50 Sodium hydroxide g 2 Sodium hydroxide g 3Water 'm 1000 Water mm... 1000 B B CaHa-CN 00 -r r 28-OHg-r-CN 5 I%\o/JCHrC0GHs g.. 8

o Methanol ccm 100 Methanol Mm 100 n u d m lbl'unalltddutob.

mom 3 Forms 7 A A N-N diethyl-para-phenylenediamine N-Ndiethyl-para-phenylenediamine H01 3;. 2 RC1 g 2 Sodium sulphite(ct-yet.) as Sodium sulphlte (cl-yet.) ..gts carbonate (crystJu -g 00Sodium carbonate (crystJ ..g.. Sodium hydroxide g 2 Sodium hydroxide g 2Water 7 1 com 1000 Water y can" 1000 Organic solvents, for instanceacetone, alcohols or the like, may be used to dissolve the colorcouplers.

The invention is in no way limited to the use oi the color couplers inthe developing solution itself.

Thus as above stated, one o! the essential products, the color coupler,which during the development forms the dye, can also be added to thephotographic emulsion (for instance by adsorption upon the silver salts)before or after coating. The other ingredients of the color formingbaths, containing chiefly the aromatic amino developer, may be appliedlater, during the developing process. as a bath.

The present invention may be utilized in the formation of coloredphotographic images on plates or papers as well as on films, employinggelatine or some other carrier substance :lor the silver halide.

The developing process may be used for developing photographic material,provided with one or more sensitive layers, which are, applied on oneside or on both sides of the support.

The silver formed during the developing process may be eliminated. Forthis purpose a bath should be used, however, which does not destroy thedye. Thus, a bath consisting of a solution in water of potassiumferricyanide and sodium thiosulphateeasily eliminates the silver withoutdestroying the dye, leaving a pure dye image.

We do not wish to be limited to the exact details of the invention asdescribed in the foregoing specification as various modifications willoccur to a person skilled in the art.

We claim:

1. The process of developing a colored image in a. gelatin-silver halidephotographic layer which comprises coupling the development product of aprimary aromatic amino developing compound with the coupler compound, 3benzyl-5 acetonyll,2,4-oxodiazole 2. The process of developing a coloredimage in a gelatin-silver halide photographic layer which comprisescoupling the development productof a primary aromatic amino developingcompound with the color coupler compound of the general formula whereinX is an electro-negative organic radicalselected from the classconsisting of acyl and cyano, while Y is an organic radical of the classconsisting of substituted alkyl.

HONORE VERKINDEREN, NORBERT VANKEIRSBILCK.

